The Statistics and Data Management Core will provide consultation and services to Center investigators in the areas of data management and statistics, performing analyses as required by project investigators, acting as a resource center for statistical and scientific continuing education in data analysis among project investigators. Special challenges exist in designing, operating, and analyzing studies in cancer prevention and control. A wide variety of study designs and analytical techniques can be applied to such studies -- ranging from sample surveys to randomized clinical trials to nested case-control studies. The statistical core unit will e built around existing statistical capabilities in the Cancer Prevention and Control Program of the UCSD Cancer Center and the Biostatistics Core Unit of the UCSD Cancer Center. The Core will draw strength not only from existing personnel, but also from the prior development of methods for designing, executing, and analyzing studies similar to those in the proposed Center.